Circuit connection for and method of operating alternating motors.



No. 823,220. PATENTED JUNE 12, 1906. D. C. JACKSON.

CIRCUIT CONNECTION FOR AND METHOD OF OPERATING ALTERNATING MOTORS.

APPLIOATION FILED MAY 16. 1904.

3 SHEETSSHEET l.

No. 828,220. PATENTED JUNE 12, 1906. D. O. JACKSON.

CIRCUIT CONNECTION FOR AND METHOD OF OPERATING ALTERNATING MOTORS.

.APPLIOATION FILED MAY 18. 1904.

3 SHEETS-SHEET 2.

No. 823,220. PATENTED JUNE 12 1906.

D. O. JACKSON. CIRCUIT CONNECTION FOR AND METHOD OF OPERATING A LTERNATING MOTORS.

APPLICATION FILED MAY 16. 1904.

3 SHEETS-SHEET 3.

We? Du aid [1 Jacksmr :5

. EEEEE:

UNITED STATES PATENT OFFICE.

DUGALD C. JACKSON, QF MADISON, WISCONSIN. CIRCUIT CONNECTION FOR AND METHOD OF OPERATING 'ALTERNATING MOTORS.

Specification of Letters Patent.

Patented June 12, 1906-.

To all whom it may concerma Be it known. that I, DUGALD C. JACKSON, a citizen of the United States, residing at Madison, in the county of Dane and State of VViscousin, have invented a certain new and use ful Improvement in Circuit Connections for and Method of Operating Alternating Motors, of which the following is a full, clear, concise, and exact description, reference be ing had to the accompanying drawings, forming a part of this specification.

My invention relates to the operation of alternating-current electric motors; and its object is to provide improved means and an improved method for starting such motors'for varying their speeds and for proportlonately dividing the llIlE-PIBSSUIQ between several motors connected 1n series.

My invention, therefore, has particular application to electric motors used in the service of electric traction or in other service where speed variation and control is desired. For instance, in electric traction service four motors mounted on the four axles of an eight-wheel electric-railway car may be connected in series. In this case some difiiculty and embarrassment arise in aflordin means for getting all of the motors starts at approximately an equal rate, and there is also difficulty experienced under some conditions in maintaining the several serially-connected motors all at the same rate of working.

It is the object, therefore, of my invention to provide an advantageous and efiicient means for supplying the current to motors at starting with t e circuit-pressure duly divided between the motors, and italso rovides for maintaining a suitable apportionment of the rate of work of the motors at all speeds.

I obtain this efiicient operation and control of the motors by employing autotrans formers or equivalent ordinarytransformers.

connected w1th the motors in such' manner that the pressure of. the system is equally or otherwise suitably apportioned betweenthe various motors to thus insure the production of an equal amount of work by'eaoh motor. Various arrangements of the motor fields and armatures and the connection therewith Withthe line and transformers may belemployed, and the transformers may at the same time be used as an efficient starting and controlling/means besides serving to apportion the pressure.

:; My invention can be better and more fully explained with reference to the accompanying drawings, in which- I Figures 1 to 6 show modified arrange.- ments of the motor fields and armatures and their connection with the transformers and the line.

In Fig. 1 I have re resentedfour alternat ing-current motors t e armatures A and the fields F of which are connected serially together. A switch-arm S is adapted to travel over switch-contacts a b, c, d, and a, connected with oints a, b, c, d, and e of the winding oft e autotransformer T, and by means of the switch more or less of the auto- 4 transformer-windin 'may be included in circuit With the lineimbs 1 and 2, supplied from a generator G. The seriesof'motors is connected between the point f and the linelimb 2, and thus the motors are connected in series relation between the line-wire 1 and the line-Wire 2 when the controllin -switch S engages the contact d, and at t e same time the full line-pressure is im ressed upon the autotransformer-windin etween the point and the line-wire 2. eads g, h, andi ead om appropriate points g, h, and i on the autotransformer-winding to the points of connection between the several motors, so as to divide the line pressure equally, or in other suitable proportions, between the several motors.

When themotors are stopped, the switch S is open, and to start the motors the switchlever is moved to the starting position a and the several motors are subjected to low pressure. The. pressure upon the motors and their speed may be increased by moving the switch-lever over the contact-points 6 and c and to the point (1, .when full hue-pressure is impressed upon the motors, this pressure being equally divided between them by the autotransformer, so that they-are impelled to work at e ual rates if they are of substantially simi ar construction. If it is desired to increase. the s eed of the motors, the switch-lever may lie moved to the point e, when the pressure across the motors is increased above that of the line, and the speed will be accordingly increased. 1

The number of stops or positions in the ICU the autotransformer may be of reduced cross-sect1on from the point e to the end connected to line conductor 2, if desired, and

adopted, as shown in Fig. 3, 1n which the sev'-' eral fields are connected in a series across the main-line limbs 1 and 2, and the armatures, with their autotransformer, ma be connected as another branch between t e line-limbs.

Fig. 4 represents the arrangement applied to repulsion-motors, and here the autotransformer is connected so as to distribute the pressure ap ropriately between the fieldwindings F o the motors, and-the several armatures A A are connected in a local circuit, which ma contain a variable controller 0, by means 0 which more or less resistance or impedance may be included in the local armature-circuit and the s eed of the motors further controlled, oreac armature-circuit may be se arately closed.

ig. 5 a so represents the arrangement applied to repulsion-motors, with a second autotransformer T introduced between the terminals of the armatures A A in such a way that the pressure ma be simultaneously varied between the fiel -terminals and the induced ressure at all times be properly ap ortioned etween the armature-win ings. he fields F F are associated with the autotransformer T and the pressure across the limbs 1 and 2 thereby proportionately distributed.

The startin and controlling feature of the switch S may e utilized in both the arrangements shown in Figs. 4 and 5, although the line-limb 1 might be directly connected with some part of the autotransformer-windings.

Instead of an autotransformer an e uivalent ordinary transformer with subdivided primary or secondary coils may be emplo ed,

- and in Fig. 6 I have shown a modifie arrangement in which an ordinary transformer T is employed, and by means of the controlling-switch S more or less of the primary winding P may be bridged between the linelimbs 1 and 2, and thereby more or less pressure induced and distributed in the secondary winding'fl. The motors have their armatures A and their fields F all connected serially together and included serially in circuit with the secondary winding, appropriate My invention may also be utilizedwith 6 3 case an autotransformer may be introduced with each phase in connection with the series connected primary windings of the motors which belong to that phase, or a single autotransformer related to one phase alone may be relied upon to suitably apportion the total impressed pressure, and various other modification's may be made in the arrangement of the motor armatures and fields and their connection with the transformers and the line without departing from the scope of the invention, and I do not wish to be limited to the arrangements herein shown. I use the word transformer in the sense of either an autotransformer (which ordinarily possesses only one winding) or an ordinary transformer wit a plurality of windings.

I claim as new and desire to secure by Let.- ters Patent 1. The combination with a plurality of alternating-current motors connected serially in a circuit bridging between the limbs of an pressureproportionatelydivided betweensaid motors.

3. The combination with a plurality of alternating-current motors connected serially in a circuit bridging between the limbs of an alternating-current circuit, of an autotransformer for dividing the line-pressure proportionately between said motors.

4. The combination with a plurality of alternating-current motors connected serially in a circuit bridging between the limbs of an alternating-currentcircuit, of transformer means for dividing the line-pressure proportionately between windings of said motors.

5. The combination with a plurality of alternating-current motors connected serially in a circuitbridging between the limbs of an alternating current circuit, of autotransproportionately between wlndings of said motors.

6. The combination with a plurality of alternating-current motors connected serially in a circuit bridging between the limbs of an alternating-current circuit, of transformer means for dividing the line-pressure proportionately between the fields of said motors, and transformer means for dividing the pressure proportionately between the armatures of said motors. v

7. The combination with a plurality of a1 alternating-current circuit, ofmeans for mainformer means for dividing the line-pressure Y ternating-current motors connected serially in a circuit bridging between the limbs of an alternating-current circuit, of an autotransformer for dividing the line-pressure proportionately between the. fields of said motors, and an autotransformer for dividing the pressure proportionately between the armatures of said motors.

8.- The combination with an autotransformer having its winding connected between the limbs of an alternating-current circuit, of a plurality of motors connected serially together, terminals of said motors being connected with appro riate intermediate points on said autotrans ormer-winding.

9. The combination with a transformer having a winding, connected between the limbs of an alternating-current circuit, of a plurality of motors connected serially together, the terminals of said motors being connected with appropriately-separated points on a winding of said transformer.

10. The combination with a plurality of alternating-current motors connected serially together, the terminals of said motorsbeing connected with appropriate points on a winding of a transformer, and means for including more or less of a winding of said transformer in circuit between the limbs of an alternating-current circuit. 7

11. The combination with an autotransformer, of a plurality of alternating-current motors connected serially together, the terminals of said motors being connected with appropriate oints on the autotranstormer- Winding, an means for includin more or less of said winding serially in circuit with the line-limbs of an alternating-current circuit.

12. The combination with a plurality of alternating-current motors, or" electromagnetic means for maintaining at the several motors fixed proportions of the total load delivered by the circuit.

13. The combination with the winding of a transformer, of a plurality of alternating-current motors connected seriallytogether, terminals of said motors bein connected with appropriate points on said winding, and switching means for including more or less of said windingin circuit with the limbs of an alternating-current-supply circuit.

14. The combination with a plurality of alternatin -current motors connected together an in circuit with the limbs of an alternating-current-supply circuit, of means for dividing the line-pressure proportionately between said motors, and means for increasing the pressure across said motors above that of the line.

15. The combination with a plurality of alternating-current motors connected serially together and with the limbs of an alternatingcurrent-supply circuit, of transformer means for dividing the line-pressure proportionately ropriate between said motors, and means for varying the pressure across said ser1es of motors.

16. The combination wrth a plurality of alternating-current motors connected serially together and with the limbs of an alternatingcurrent-supply circuit, of an autotransiormer for dividing the pressure proportionately between said motors, and means for varying the pressure across said series of motors.

17. The combination with an autotransformer, of a series of motors connected together in bridge about part or all of said autotransformenwinding, intermediate terminals of said motors being connected appropriate intermediate points of the transformerwinding, and means for including different portions of said transformer-winding incircuit between the limbs of an alternating-current-s11 ly circuit. 7

18. The combination with an autotransformer, of a series of motors connected serially together and bridged about part or all of said autotransiormer-winding', intermediate terminals of said motors being'connected with appropriate intermediate points on the transformer-winding, and switching means for including different lengths of said transformerwinding in circuit between the limbs of an alternatin -current-supply circuit.

19. T e combination with a transformer connected with an alternating-current-supply circuit, of a series of alternating-current motors connected serially together, each rhotor of the series being bridged across an apropriate part of a winding of said transiormer, and means for varying the pressure in said transformer-winding.

20. The combination with a transformer connected with an alternating-current-supply circuit, of a series of alternating-current motors connected serially together, each motor of the series being bridged across an apart of a windin of said transormer, an means for changing the points or a point on a winding of the transformer at which the-saidsupply-circuit connects with the said transformer-windin s.

21, The combination wit an autotransformer connected with an alternating-current-supply circuit, of a pluralit of alternatin -current motors, the fields c said motors being serially connected together and the terminals thereof connected with appropriate points on the transformer-windin and an KOO independent circuit connected wi the arincluding any part of said winding in said supply-circuit, the armatures oi said motors bemg connectedserially together, and an additional autotransformer connected from ap-. propriate points with the terminals of,sa1d armatures.

23. The combination, with a plurality of alternating-current motors connected serially togetherin an alternating-current circuit, of an'autotransformer, and parts of the winding of said transformer, one of the said parts bemg bridged abouta winding or windings of each motor.

24. The combination, with a plurality of alternatin -current motors connected seri-' ally toget er in an alternating-current circuit, of an autotransformer, parts of the winding of said transformer, one of said parts be ing bridged about a winding or windings of each motor, andmeans for-varying the pressure per unit of length impressed on said trans 'ormer-winding. I H

25. The method of operating a roup qf alternating-current motors connecte serially together, which consists in subjecting each motor to the influence of art of an inductive winding to proportion tl ie pressure between the motors, and varying the pressure across said group of motors.

v 26. The method of operating a group of alternating-current motors connected serially in circuit, which consists in subjecting said motors to the influenceof interrelated inductive windings to equalize or to pro ortion the pressure between the motors, an varying the pressure across said motors by ineluding more or less of the windings in the supply-circuit.

27. The method of causing motors which are connected to ether in series to deliver equal amounts or work, which consists in equalizing the pressure at the motors by subjecting each motor to the infiuence of an appropriate portion of inductance included in the supply-circuit. s

28. The combination with a plurality of armature-windings of alternatingscurrent dytrical pressures 55.

namos, of means or maintaining a fixed pro portion ofthejoint load on each armature- -29. 'lhe combination of a load or interrelated loads tobe-driven by'a plurality of alternating-current motors connected in series relation, and means for equalizing the elecapplied to the individualof a phase between a which consists in subjecting 1 seams plurality of motor-windings connected in series relation, the terminals of said motorwindings being conductively related with oints on the winding of the said autotransormer. s

32. The combination with'a polyphase alternating-current circuit, of serially-connected motorwindings associated with each phase, and means inde endent of the motors for proportionally ividing the pressure 'etween the windings associated therewith.

33. The method of compensating the load between a pluralit of alternating-current motors with seria ly-connected wind' s, which consists in subject the series to t 6 total working pressureffividing the said pressure into proportional parts independently of the efiect of the motors, and maintaining one of said parts impressed upon the wind' s of each motor. r 34. he method of compensating the load plurality of alternating-current motors wit serially-connected wind s, which consists in subjectin the series to t e total working pressure, pressure into equal parts independently of the effect of the motors, and mamtainingone of said parts impressed upon the windings of each motor.

35. The method of compensating the load between a lurality of alternating-currentmotors witii serially-connected windin s, which consists in subjecti total workingpressure, ivid' the said pressure intoproportional parts y electroma netic means independently of the effect of 51c motors, "and mainta' one of said parts impressed upon the win ings of each motor.

36. The method of compensating the load between a plurality of alternating-current motors wit the series to t e total working pressure, viding the said ividing the said the series to t e Ico serially-connected windin s,

no I

pressure into e ual parts by electromagnetic I means indepen en'tly of the effect of the mo tors, and maintainin one of said parts impressed upon the win ings of each motor.

37. The method of simultaneously starting and controlling a plurality of alternating-current motors 1n series circuit which consists in subjecting the series to an electrical pressure establishing a, fixed division of the said total pressure into proportional parts, impressing apart upon each motor, and varying the total pressure. 1

38. The method of simultaneously starting and controlling a plurality of alternating-current motors in series circuit which consists in subjecting the series to an electrical pressure, establishing a fixed division of the said total pressure into equal parts, impressing a part upon each motor, and varying the total pressure.

39. The method of simultaneously starting and controlling a plurality of alternating-current motors in series circuit which consists in subjecting the series to an electrical pressure, establishing division of the said total pressure into proportional parts by electromagnetic means, impressing a part upon each motor, and varying the total pressure.

40. The method of simultaneously starting and controlling a plurality of alternating-current motors in series circuit which consists in subjecting the series to an electrical pressure, establishing a division of the said total pressure into equal parts by electromagnetic means, impressing a part upon each motor, and varying the total pressure.

passing the current for each motor through inductive windings and causing the currents of each of the several motors to react on the circuit of each of the other motors.

42. The method of equalizing the load of alternating-current motors which consists in interlinking the circuits of the several motors by magnetic flux and thereby preventing an unproportional division of the povven.

In Witness whereof I hereunto subscribe 0 my name this lth day ofMay, A. D. 1904.

DUGALD C. JACKSON.

Witnesses:

WM. B. JACKSON, DORA E. CASEY. 

